Compressor



C. C. SPREEN COMPRESSOR June 17, I 1930,

Filed Nov. 7, 1927 INVENTOR,

6%47 765 G. aapreer? ATTORNEYfi,

Patented Ju e 11, 1930 UNITED. sures PATENT OFFICE CHARLES O.

SPREEN, OF DETROIT, MICHIGAN, ASSIGNOR TO KELVINATOR CORPORA- TION, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN oomrnnsson Application filed November 7, 1927. Serial No. 291,499.

This invention relates to compressors, and

more particularly to compressors forming a.

part of refrigerating apparatus, the present application being a continuation in part of my co-pending application Serial No. 145,157, filed October 30, 1926.

An object of my invention is to increase the eificiency of compressors of the character above set forth by providing complementary piston and cylinder head surfaces so that there is a-uniform space therebetween at the completion of the compression stroke allowing unrestricted exhaust of the compressed refrigerant.

A further object of the invention is to increase the efficiency of compressors of the character above set forth by providing a direct communication between the refrigerant inlet and thecompression chamber, other than the inlet ports through a piston, thus trapping refrigerant of a quantity to completely fill the entire area of the compression chamber when the piston starts the compression stroke.

Another object of my invention is to utilize the fastening device for the cylinder head plate to secure the exhaust valve.

Still another object of my invention is to provide a compressor structure in which oil returning to the compressor with refrigerant the following description which sets forth 'a' preferred embodiment of the invention.

In the accompanying drawings, Fig. 1 is a central vertical sectional View of a compress'or structure embodying my invention; and Fig. 2 is a fragmentary sectional view of the same taken on line 2-2 of Fig. 1.

Referring now to the-drawings by charac ters of reference, 10 represents a compressor cylinder within which is arranged a sleeve 11'. lQhe upper end of the cylinder is closed by the head plate 12 and a valve housing. 13 rests upon the head plate, the valve housing and head plate being secured to the cylinder by 2 bolts 14. A piston 15 is arranged to reciproi cate within the sleeve, and is operated by the rod 16 connected to the pin 17 which traverses the piston. The space 18 Within the sleeve, in-. termediate the piston head 19 and the inner face 20 of the cylinder head, defines the compression chamber for expanded refrigerant, or similar gases.

The compressor head is provided with an outlet passage 21 extending centrally therethrough, and exhaust valve mechanism is associated therewith interiorly of the housing 13, such mechanism being of a character. similar to that shown in my Patent No. 1,568,195, issued January 5, 1926. The upper wall of the head plate is formed with a circular groove 22 providing a circular flange 23 adjacent the outlet passage 21 and a thin metal closure disc 24, for the outlet passage, is arranged to engage with the seat flange 23. .A movable stop member is associated with the disc and includes an inverted portion 25, and legs 26 which seat within the groove 22. A coil spring 27 extends intermediate the stop member and the disc permitting a limited opening movement of the .disc before it engages the inverted portion 25 of the stop member. A cage 28 surrounds the stop member and is provided with a flanged base 29 which extends between the valve h0us-' mg 18 and the, head plate and is securely clamped in stationary position-therebetween by the bolts "14. A coil spring 30 is arranged between the cage and-the stop member and exerts a greater pressure'than the other spring. When the disc is-lifted from its seat by compressed refrigerant overcoming the tension of the spring, refrigerant passes throughslots 31 and aperture 32 inthe cage and into the valve housing fromwhich it passes through the aperture 33. The end wall and close the outlet passage when refrigerant pressure in the compression chamber issufficiently reduced due to the relief opening in the stop member, thus increasing the efiiciency of the compressor. The manner of securing the valve cage has the advantage of eliminating separate fastening meansfland reducing the time required to attach and detach the same in order to service the valve mechanism.

The cylinder is preferably formed to provide an annular refrigerant inlet chamber which surrounds a portion of the sleeve, the sleeve being provided with a pair of oppositely disposed slots 36 extending axially of the sleeve and in open communication with the inlet chamber. chamber preferably below the. inlet opening 38, extends lower than the slots 36, so that oil entering thechamber with the gasified ref frigerant will fall by gravity to the bottom of the chamber and will drain through the passage 39 into the crank case (not shown).

With this construction of cylinder, substantially only oil in vapor form will pass into the compression chamber through the slots The piston is provided with a pair of radially extending passages 4Qwhich extendthrough' the side of the piston and terminate in an annular'chamber- 41 interiorly of the head, the passages being associated in open communication with the slots 36 in the sleeve.

The distance between the inlet of the pas sages 40 and the piston head is such that when .the piston approaches retracted position, the

piston head will uncover the upper end of the slots '36 and establish direct'communication between the intake chamber and the com pression chamber above the piston.' A plurality of passages 42 arranged in circular relation, extendthrough the head of the piston and establish communication between the chamber 41and the compression chamber.

Valve mechanism is associated with the.

piston head to control the refrigerant passing member 45 having a neck 46 which extends through the opening in the valve member. A countersunk bolt 47 extends through the clamping member and fastens it to the piston head, a lock washer 48 eing A portion 37 of the intake arranged between the bolt head and the clamping member. The clamping member overlies and secures the inner portion of the valve ring, and permits the outer portion thereof to flex upwardly when the piston is moving downwardly, thus allowing refrigerant to pass from the chamber 41 to fill the compression chamber. As stated above, the

interior wall of the cylinder head and the outlet passage therethrough are complemen tary to the end of the piston including the associated valve and clamping means, so that unrestricted flow through the outlet assage- 21 is attained, thus increasing the e ciency of the compressor andsubstantially preventing reexpansion of compressed refrigerant in the expansion chamber upon the return stroke of the piston.

As the piston moves downwardly the valve 31 will open, and it tends to remain open as the piston approaches the bottom of its stroke,

and also during the first part of the compression stroke, because the pressure of the refrigerant in the intake chamber is greater than that which has assed into the compression' chamber. Un er such conditionsv the valve will close only as the piston compresses the refrigerant in the compression chamber sufliciently to overcome that in the intake chamber, thus reducing the quantity of refrigerant which the capacity of'the compression chamber can retain for compression. However, by establishin communication directly between the inta e chamber and the compression chamber through the up r ends of the slots 36 which are uncovere by the piston, refrigerant pressure in the chamber becomes such that it will close the valve immediatel upon the upward stroke and thus' trap a ull capacity of refrigerant in the compression chamber and thus increase the eificiency of the compressor.

Although I have illustrated but one form of my invention and have described in detail but a single application thereof, it will apparent to those skilled in the art that it is not so limited but that various modifications and chan es may be made therein without departing rom the spirit of my invention or the scope of the appended claims.

What I claim is:

1. In a compressor, the combination of a cylinder, a cylinder head extending across said cylinder, a valve housing seated upon said cylinder head, exhaust valve mechanism including a cage, and means for securing said housing to said cylinder head, said valve cage having a portion clamped between said ing a flat and centrall disposed abutment portion for engaging t e disc when the latter is in raised position, said ortion having an aperture therethrough, an spring means intermediate said disc and said stop member.

In testimony whereof I hereunto a'fiix my signature;

CHARLES C. SPREEN. 

